An internet search engine is a tool typically designed to search for information on the World Wide Web. Users submit search queries to the search engine and the search engine identifies and presents a list of result documents in response to each search query. The list of result documents consists of links to webpages, images, and other types of files, typically identified and retrievable by their Uniform Resource Locators (URLs). To identify documents and items that are most relevant to a user's needs and to present them in a manner that is most useful to the user, the list of result documents can be ranked according to various relevance and quality parameters before being presented to the user.
User actions with respect to each result document presented in response to a search query submission can serve as feedback that is indicative of the relevance and quality of the result document with respect to the search query. User feedback data for each result document can be collected from multiple users and aggregated over time, and statistics of the aggregated user feedback data for the result document can be used to adjust the ranking of the document in the result list for future submissions of the search query.